partially fogged film ?

[Clay Turtle]

Ah, yes I use a rather large cloth I had made up, generally I cover the full length of the camera (from the front standard to the rear standard) as well as keeping it shut (closed) during exposures.

Sorry about the spelling error (typing) but your response came as I was shutting down.
To an extent there is necessity of leaving the back covered: I would point out that as I intend to build an 8x10, necessary info is the size of the film holder [ => standard, etc] for such a build I bought some online. One thing I did note about these holders is that the greater distance (length of the sides tends to allow more flex) such that when the slide was removed the side wall bowed opening a gap which would allow light to fog the film in the holder. Of course these are used plastic holders of larger format than the 4x5. It convinced me that precautionary leaving the dark cloth in place would best serve as a procedure.
It paid off in short order. I was using the 5x7 which is a build in progress but not have any gg. for it I used an Bender kit camera [that was part of the base unit on which the build was being made] as the film holder / gg section fit nicely into the hole (cross sectional area) in the 5x7 back, the only problem was it didn't extend to the edge which meant , it was secured in place. I had taken one shot [back ground are (upper portion) & turned the camera about 90 degrees to do the second when the sprinkler system came on. A moment of blind panic . . . fight or flight syndrome was over come as I watched & noted that the nearest rainbirds clicking away weren't patterned to water the area where I was set up. As I was already holding the release cable in hand I decided to chance it & took the shot. Now I was still vaguely feeling that flight emotion & was about to remove the dark cloth rather than going under it (after all it was still dark out) to re-insert the slide. But good procedure won over & I only lifted the dark cloth finding that 4x5 bender part was in fact caught in the folds of the cloth as it had fallen away from the back plate. If I had simply removed the dark cloth, holder & all would have fallen exposing (fogging) the slide film.

[Clay Turtle]

One thing I did note about these holders is that the greater distance (length of the sides tends to allow more flex) such that when the slide was removed the side wall bowed opening a gap which would allow light to fog the film in the holder. Of course these are used plastic holders of larger format than the 4x5. It convinced me that precautionary leaving the dark cloth in place would best serve as a procedure.

Added tidbit of info. Later you may ask yourself why or what is the difference between plastic & wooden holders? Important aspects swelling vs expansion & contraction vs heat absorbtion & thermal decomposition.

[gbogatko]

I've had a nasty fogging problem with an 8x10 holder -- the whole sheet fogs up on both sides of holder B, no problem with holder A. Holder A used under the sky, holder B in shade. Examination of holder B (the fogging one) shows signs of some kind of repair along both edge seams. I've bit the bullet and ordered 2 new ones.

george